Driving control method and driving control device

Abstract

A processor 10 in which this driving control method is implemented executes first driving control at a first driving level when a first travel environment condition is satisfied, and executes second driving control at a second driving level more advanced than the first driving level when a second travel environment condition is satisfied. A second lane change condition for determining whether to execute second lane change control under the second driving control is set so as to be more strict than a first lane change condition for determining whether to execute first lane change control under the first driving control. When it is determined that the travel environment detected during the execution of the first driving control satisfies the second travel environment condition, it is determined whether lane change control is necessary within a predetermined distance from the current position of a host vehicle V1. If it is determined that lane change control is necessary, the process of transitioning from the first driving level to the second driving level is stopped, and if it is determined that the lane change control is not necessary, the driving control is transitioned from the first driving level to the second driving level.

Description

Driving control method and driving control device

[0001] The present invention relates to a vehicle driving control method and a driving control device.

[0002] There has been known a device that maintains the driving level by reducing the vehicle speed when lowering the driving level of automatic driving as the vehicle speed increases.

[0003] Japanese Patent Laid-Open No.2020-29238

[0004] When the driving level is automatically increased due to satisfaction of conditions, there is a possibility that automatic lane change cannot be performed due to the increased driving level.

[0005] The problem to be solved by the present invention is to avoid a situation where automatic lane change cannot be performed due to an increased driving level.

[0006] According to the present invention, when a first driving environment condition is satisfied, a first driving control based on a first driving level is executed, and when a second driving environment condition is satisfied, a second driving control is executed based on a second driving level that is higher than the first driving level. A second lane change condition for determining whether the second lane change control can be executed under the second driving control is set to be relatively stricter than a first lane change condition for determining whether the first lane change control can be executed under the first driving control. When the second driving environment condition is satisfied during execution of the first driving control, if it is determined that lane change control is required within a predetermined distance from the current position of the own vehicle, the process of transitioning from the first driving level to the second driving level is canceled; otherwise, the transition from the first driving level to the second driving level is performed, thereby solving the above problem.

[0007] According to the present invention, it is possible to avoid a situation where automatic lane change cannot be performed due to an increased driving level.

[0008] Fig. 1 is a block diagram showing a hardware configuration of a driving control system. Fig. 2 is a flowchart showing a processing procedure of driving control. Fig. 3 is a diagram explaining the movement of an own vehicle on a road that merges after branching.

[0009] <First Embodiment> Figure 1 shows the hardware configuration of a driving control system 100 equipped with a driving control device 1 according to this embodiment. This driving control method performs driving control to automatically drive the vehicle to be controlled. This driving control method is implemented using each piece of hardware of the driving control system 100, including the processor 10 of the driving control device 1. The driving control system 100 includes one or more sensors 2, a vehicle information acquisition device 3, an other vehicle information acquisition device 4, a navigation device 5, a vehicle actuator 6, and an input device 7. The driving control device 1 and each of the above devices are connected by CAN (Controller Area Network) or other wired / wireless in-vehicle LAN and exchange information with each other. Each device may be a device mounted on the vehicle, or it may be a portable terminal device that can be brought into the passenger compartment and connected to the in-vehicle LAN.

[0010] Multiple sensors 2 are installed on the vehicle, forming a group of sensors that work together. Sensors 2 detect the presence or absence of objects, including other vehicles, around the vehicle, the distance to the objects, the relative velocity of the objects, and the relative acceleration of the objects. Sensors 2 also detect other vehicles traveling in front of, behind, and to the left and right sides of the vehicle (oncoming lane, adjacent lane, and adjacent adjacent lane).

[0011] Sensor 2 includes one or more cameras 21 positioned on the vehicle. One or more cameras 21 capture images of the vehicle's surroundings in all directions. Cameras 21 include image sensors equipped with image elements such as CCD (Charge Coupled Device) or CMOS (Complementary Metal Oxide Semiconductor), ultrasonic cameras, or infrared cameras. Sensor 2 includes a radar device 22 that detects (measures distances to) the presence, position, and positional changes of objects around the vehicle. The radar device 22 measures the distance and direction to an object by emitting electromagnetic waves toward the object and measuring the reflected waves. The radar device 22 includes laser radar, millimeter-wave radar, LiDAR (light detection and ranging) unit, ultrasonic radar, or sonar. Sensor 2 can acquire information about the surrounding environment from an external information provider via a communication device provided by the driving control device 1. The information provider may be an external server that collects detection information from sensors installed on the roadside. Sensor 2 can acquire information about other vehicles, including their speed, and information about the surrounding environment of other vehicles through vehicle-to-vehicle communication via communication devices provided by the driving control devices of other vehicles and its own vehicle. Each sensor 2 outputs the acquired detection information to the vehicle information acquisition device 3, the other vehicle information acquisition device 4, or the processor 10 in response to a request or command. The processor 10 may acquire detection information directly from the camera 21 and radar device 22, or it may acquire detection information via the vehicle information acquisition device 3 and the other vehicle information acquisition device 4.

[0012] The vehicle information acquisition device 3 calculates the vehicle's current position, attitude, speed, acceleration, behavior, and direction of travel based on detection information acquired from the sensor 2, and provides this information to the processor 10. The vehicle information acquisition device 3 includes a position detection device 31. The position detection device 31 receives positioning signals from a GNSS (Global Navigation Satellite System) and detects the vehicle's position. The position detection device 31 includes an IMU (Inertial Measurement Unit). The IMU is an inertial measurement device that detects three-dimensional inertial motion, and by measuring the tilt and acceleration of three axes, it detects the vehicle's relative position information and attitude. The position detection device 31 further detects the vehicle's position using detection information from a gyro sensor and / or detection information from a vehicle speed sensor. The position detection device 31 detects the position (current position) of the moving vehicle over time and detects the position at each point in time. The position detection device 31 may also be provided in the navigation device 5, which will be described later. The position detection device 31 provides the detection results to the processor 10. The other vehicle information acquisition device 4 calculates the position, attitude, speed, acceleration, behavior, and direction of travel of objects, including other vehicles, around the vehicle based on the detection information acquired from the sensor 2, and provides this information to the processor 10.

[0013] The navigation device 5 calculates a route to a set destination by referring to map information 51 and lane information 52. This route includes a target trajectory in which the lane to be driven is identified. The route and target trajectory calculated by the navigation device 5 are provided to the actuator 6 and used for autonomous driving. The map information 51 and lane information 52 are recorded in an in-vehicle storage device or an external server accessible via a communication device provided by the processor 10. The map information 51 is high-precision map information that includes lane information 52 which is referenced in the execution of automatic lane change control. The lane information 52 includes identification information that identifies each of the multiple lanes belonging to the road. The navigation device 5 includes a touch panel type display 53 that accepts input and a speaker 54 with a built-in microphone. The navigation device 5 presents information to the driver via the display 53 and / or speaker 54 and accepts input from the driver.

[0014] The actuator 6 comprises a steering device 61, a drive device 62, and a braking device 63. The actuator 6 acquires command values ​​for automatic driving control according to a driving plan formulated by the processor 10, and drives the vehicle to automatically travel along the route to the destination in accordance with the input of longitudinal and lateral forces that control the vehicle's driving position based on the command values. The command values ​​may include only lateral force (steering), only longitudinal force (driving / braking), or both lateral and longitudinal force. The driving control may operate only the steering device 61 of the actuator 6, only the drive device 62 and braking device 63, or both of these.

[0015] The input device 7 receives input from the driver and provides it to the processor 10. Input using the input device 7 is performed by pressing a switch located near the driver's seat, steering the steering wheel, etc. Alternatively, the touch panel of the display 53 of the navigation device 5 and the microphone provided in the speaker 54 can be used as input devices 7. The input device 7 notifies the driver of the execution of automatic lane change control using the navigation device 5 and accepts confirmation input from the driver.

[0016] The processor 10 of the driving control device 1 performs both autonomous driving control, which automatically drives the vehicle, and manual driving control, which includes manual driving based on driver input. The processor 10 includes a ROM (Read Only Memory) 12 that stores programs for controlling automatic or manual driving, a CPU (Central Processing Unit) 11 that executes the programs stored in the ROM 12, and a RAM (Random Access Memory) 13 that functions as an accessible storage device. In this embodiment, the processor 10 executes each function by coordinating software that realizes the function of transitioning driving levels and the function of executing autonomous driving control, including lane changes, with the hardware of the driving control system 100 shown in Figure 1.

[0017] The processor 10 controls the transition (change) of the driving level. In this embodiment, the first driving level is a driving level lower than the second driving level. The specific stages (numerical values ​​of the driving levels) of the first and second driving levels are not limited. The driving level is a level that indicates the degree of intervention by the driver through manual driving when assisting the driving of the vehicle. The higher the driving assistance level, the lower the contribution of driver operation to the driving of the vehicle. In other words, in this embodiment, the first driving level is a driving level in which the driver's contribution is higher than that of the second driving level. The definition of the driving level is not particularly limited, and the driving level may be defined based on SAE J3016 of the Society of Automotive Engineers (SAE), or based on ISO / TC204 of the International Organization for Standardization (ISO). For example, five levels of driving may be defined depending on the degree of driver intervention through manual driving, such as: Driving Level 1: Driving assistance in either the longitudinal or lateral direction; Driving Level 2: Partially automated driving in both longitudinal and lateral directions within a limited area; Driving Level 3: Conditional automated driving; Driving Level 4: Highly automated driving under specific conditions; Driving Level 5: Fully automated driving. The driving entity for Driving Levels 1 and 2 is the driver, while the driving entity for Driving Levels 3 through 5 is the driving control system. Hands-on operation by the driver is required for Driving Levels 1 and 2, while hands-off operation by the driver is not required for Driving Levels 3 through 5 (hands-off operation is permitted).

[0018] The processor 10 executes a first driving control at a first driving level if the first driving environment conditions are met, and executes a second driving control at a second driving level that is more advanced than the first driving level if the second driving environment conditions are met. The second driving environment conditions that permit the execution of the second driving control at the second driving level are conditions that define an environment that is easier to perform autonomous driving than the first driving environment conditions that permit the execution of the first driving control at the first driving level. The driving environment defined by the second driving environment conditions is a driving environment that is more suitable for performing advanced autonomous driving than the driving environment defined by the first driving environment conditions. Specifically, with respect to curvature, the curvature of the second driving environment conditions is defined to be smaller than the curvature of the first driving environment conditions. With respect to lane width, the lane width of the second driving environment conditions is defined to be larger than the lane width of the first driving environment conditions. With respect to branching and merging, the second driving environment conditions are defined to have no or few branching and merging, while the first driving environment conditions do not have such restrictions. Regarding weather conditions, the rainfall amount for the second driving environment condition is defined to be smaller than that for the first driving environment condition. Regarding the accuracy of lane mark detection / recognition, the accuracy for the second driving environment condition is defined to be higher than that for the first driving environment condition. The first and second driving environment conditions are arbitrarily defined for each driving level. Additionally, a moderate vehicle speed (e.g., 50 km / h to 100 km / h) may be added as a second driving environment condition. This helps to suppress level increases. Vehicle speed refers to the speed of vehicles traveling in the driving lane or adjacent lanes. The processor 10 can also acquire necessary information from external sources such as infrastructure to determine whether the second driving environment condition is met or not.

[0019] Driving environment conditions can be defined based on static information such as the attributes of the road including the lane in which the vehicle is traveling (lane width, whether it is a dedicated road or not, speed limit), lane shape (curvature, lane width), presence or absence of lane merges / divisions, and whether or not the number of lanes decreases, as well as "dynamic information" such as congestion information for each lane, current or future weather (rain / snowfall), road surface conditions (wet / snowy / icy), detection accuracy of lane markings for each lane, and recognition accuracy of lane markings.

[0020] Different driving levels result in different control methods for driving and lane changes. At the first driving level, the first lane change control is performed by the first driving control, while at the second driving level, the second lane change control is performed by the second driving control. The conditions for determining whether or not to perform the second lane change control are set more strictly than the conditions for determining whether or not to perform the first lane change control. The conditions for the second lane change are defined more restrictively than the conditions for the first lane change. The lane change conditions include conditions based on vehicle speed and / or conditions based on the distance or time between vehicles traveling in adjacent lanes (= vehicle speed distance / vehicle speed). The second vehicle speed range for the second lane change conditions at the relatively higher second driving level is narrower than the first vehicle speed range for the first lane change conditions at the first driving level. Vehicle speed ranges may be defined for each driving level, each road attribute, each speed limit, and each vehicle performance. For example, if the first driving level is "2", the first speed range for the first lane change condition may be defined as the entire speed range, and if the second driving level is "3", the second speed range for the second lane change condition may be defined as 60 km / h or more. Following time is calculated based on the speed limit or actual speed of the driving lane or adjacent lane. The second following distance range for the second lane change condition is narrower than the first following distance range for the first lane change condition. Following distance ranges may be defined for each driving level, each road attribute, each speed limit, and each vehicle performance. For example, if the first driving level is 2, the first following distance range for the first lane change condition may be defined as the entire following distance range, and if the second driving level is 3, the second following distance range for the second lane change condition may be defined as 17 m or more.

[0021] When driving is performed under the first driving control at the first driving level, the first lane change control can be executed if the first lane change condition is met. Similarly, when driving is performed under the second driving control at the second driving level, the second lane change control can be executed if the second lane change condition is met. As mentioned earlier, as the driving level increases, the lane change conditions become stricter (more limited). When the driving environment of the vehicle's lane is good and the driving environment conditions for a higher driving level are met, the driving level increases. As the driving level increases, the lane change conditions become stricter. When the lane change conditions become stricter, there may be cases where the lane change conditions cannot be met and lane change control cannot be executed. Thus, if the driving level is automatically increased when the driving environment conditions are met, there is a possibility that the automatic lane change control may become impossible to execute due to the increased driving level.

[0022] The processor 10 determines whether lane change control is necessary within a predetermined distance from the vehicle's current position if the second driving environment conditions are met during the execution of the first driving control at the first driving level. The determination of whether lane change control is necessary is made after it is determined that the second driving environment conditions are met, but before the driving level upgrade process is performed. In other words, the determination of whether lane change control is necessary is made after it is determined that the second driving environment conditions are met, but before the second driving control at the second driving level is started, and while the first driving control is being executed. The determination of whether lane change control is necessary is made by referring to the map information 51, and if there is a merge or junction within a predetermined distance in front of the vehicle on the route to the destination, it is determined that lane change control is necessary. The determination of whether lane change control is necessary may also be made by the navigation device 5. Based on the detection information from the sensor 2, the processor 10 determines that lane change control is necessary if there is an obstacle within a predetermined distance in front of the vehicle. Obstacles include parked vehicles, construction sites, accident sites, or road shoulder construction. Lane change control includes driving control that moves the vehicle laterally from the driving lane to the adjacent lane in order to avoid an obstacle ahead. Lane change control includes control that moves the entire vehicle to the adjacent lane and control that moves a portion of the vehicle to the adjacent lane.

[0023] If the processor 10 determines that lane change control is necessary within a predetermined distance from the vehicle's current position when the second driving environment condition is met, it temporarily suspends (postpones) the process of transitioning from the first driving level to the second driving level. On the other hand, if it determines that lane change control is not necessary, it transitions from the first driving level to the second driving level. In this way, even if an increase in the driving level becomes possible, the driving level will not be increased if lane change control is scheduled. This avoids a situation where the driving level automatically increases due to the fulfillment of driving environment conditions, thereby preventing the execution of automatic lane change control. Furthermore, if lane change control becomes impossible due to an increase in the driving level, the system must inquire with the driver whether or not to perform lane change control, and the driver must respond each time. In this embodiment, since lane change control is completed by maintaining the driving level, there is no need to ask the driver to perform the troublesome response work required when automatic lane change control cannot be performed.

[0024] An example of the control procedure for driving control in this embodiment will be explained based on the flowchart in Figure 2. The processor 10 performs automatic driving control at an arbitrary driving level (S1). The processor 10 acquires detection information from the sensor 2 in order to perform automatic driving control (S2). The detection information includes detection information based on imaging information from the camera 21, detection information based on observation information from the radar device 22, detection information acquired from an external server, and detection information acquired from other vehicles via vehicle-to-vehicle communication. The processor 10 acquires vehicle information, including the current position and speed of the vehicle, from the vehicle information acquisition device 3 (S3). Vehicle information is acquired from the sensor 2 or the vehicle's ECU. The processor 10 refers to the detection information from the sensor 2 and / or map information 51 and lane information 52 to acquire the driving lane in which the vehicle is traveling and the position of adjacent lanes adjacent to the driving lane as part of the vehicle information. The processor 10 acquires information about other vehicles from the other vehicle information acquisition device 4, such as the presence or absence, position (distance), speed, and acceleration of other vehicles traveling around its own vehicle (in front of / behind the driving lane, in front of / behind adjacent lanes) (S4).

[0025] The processor 10 determines whether the first driving environment conditions are met (S5). The processor 10 continuously determines whether the first driving environment conditions, which determine whether a relatively low driving level can be performed, are met (if NO in S5, the process returns to S1). If the first driving environment conditions are met (YES in S5), the processor 10 executes the first driving control at the first driving level (S6). During the execution of the first driving control, the processor 10 continuously determines at predetermined intervals whether the second driving environment conditions are met (S7). The second driving environment conditions are the conditions for determining whether a transition to a second driving level higher than the first driving level is possible. If the processor 10 determines that the driving environment detected during the execution of the first driving control satisfies the second driving environment conditions, it does not immediately increase the driving level, but first determines whether lane change control is necessary within a predetermined distance from the vehicle's current position (S8). The determination of whether lane change control is necessary within a predetermined distance from the vehicle's current position is made after it is determined that the second driving environment conditions are met, but before the process of upgrading to the second driving level is executed.

[0026] If lane change control is required within a predetermined distance from the vehicle's current position (YES in S8), the process of transitioning from the first driving level to the second driving level is canceled (S9), even if the second driving environment conditions are met. The processor 10 cancels the level-up process and continues executing the first driving control at the first driving level (S10), and executes the first lane change control (S11). Since the vehicle has not leveled up to the second driving level, the lane change conditions are not restricted. This prevents a situation where a planned lane change becomes impossible due to an increase in the driving level, and allows the planned lane change to be completed. Once the lane change is complete, the process returns to S7, and the satisfaction of the second driving environment conditions is reassessed, and the process from S8 onwards is performed. On the other hand, if lane change control is not required within a predetermined distance from the vehicle's current position (NO in S8), the second driving environment conditions are met, and the vehicle transitions from the first driving level to the second driving level (S12). The processor 10 performs a level-up process and continues to perform the second operation control at the second operation level (S13).

[0027] Thus, even if the second driving environment conditions are met, if lane change control is required within a predetermined distance from the vehicle's current position, the system will not change from the first driving level to the second driving level. This avoids a situation where automatic lane change control cannot be performed due to the driving level automatically increasing as a result of meeting the driving environment conditions, and allows the first lane change to be performed with the first driving control at the lower first driving level. In other words, the opportunity for automatic lane change control to be performed is not lost.

[0028] In the second driving control, the processor 10 receives an input of a command to start the second lane change control from the driver of the vehicle V1 via the input device 7. In the second driving level, which is a relatively high driving level, only the command to start the second lane change control is accepted, so the second lane change control can be executed at the appropriate timing, and appropriate lane change control can be performed by the system. In addition, in the first driving control, which is a relatively low driving level, the processor 10 accepts input of driving operations for the first lane change control. The input of driving operations includes accelerator / brake input and steering input. Based on the input of driving operations, the processor 10 acquires the control timing and control amount and performs a manual driving override to modify the control content of the second lane change control. As a result, at a relatively low driving level, the system can accept the driver's input of driving operations and perform appropriate driving.

[0029] <Second Embodiment> In this embodiment, lane change control is performed taking into account the vehicle speed of other vehicles in the adjacent lane to which the lane change will take place. The processing of the second embodiment will be explained along Flow II, which is performed following the execution of the first driving control (S10) in Figure 2. The processing flow of the second embodiment is shown by a dashed line. The second embodiment is a process that can be selectively added when the second driving environment conditions are met (YES in S7), but lane change control is required within a predetermined distance range (YES in S8), so the level-up to the second driving level is canceled (S9) and the first driving control is being performed (S10).

[0030] The processor 10 obtains the speed of other vehicles traveling in the adjacent lane to which the vehicle is moving due to the first lane change control that is scheduled to be executed (S21). The speed of other vehicles may be the speed of the vehicle closest to the vehicle itself, or it may be the speed of the flow of a line of multiple other vehicles. The speed of other vehicles may be detected using the vehicle's sensor 2, detected using a sensor installed on the roadside, obtained from an external server on the road administrator's side that monitors traffic flow, or obtained from other vehicles via vehicle-to-vehicle communication. The processor 10 determines whether the speed of other vehicles traveling in the adjacent lane is above a predetermined speed (S22). If the processor 10 determines that lane change control is necessary and the speed of other vehicles traveling in the adjacent lane to which the vehicle is moving due to the first lane change control is above a predetermined speed (YES in S22), it executes the first lane change control at the first driving level (S23). Even if lane change control is necessary, it is difficult to perform automatic lane change control if the speed of other vehicles in the adjacent lane to which the lane change will take place is below a predetermined speed. In this embodiment, the traffic flow in the adjacent lane is checked in advance, and the decision to perform lane change control is made only after confirming that the traffic flow is above a predetermined speed. This makes it possible to avoid a situation where, even if the driving level is reduced to perform lane change control, the lane change control cannot be performed because the adjacent lane is congested.

[0031] On the other hand, if the speed of other vehicles in the adjacent lane is below a predetermined speed (NO in S22), the execution of the first lane change control is canceled even if a lane change is necessary (S24). In this case, monitoring of the speed of other vehicles in the adjacent lane is continued (S21), and the system waits for an opportunity when the speed of other vehicles in the adjacent lane becomes above the predetermined speed (YES in S22). In this embodiment, the traffic flow in the adjacent lane is checked in advance, and if the traffic flow is stagnant at a speed below the predetermined speed, the execution of the lane change control is canceled. This makes it possible to avoid a situation where, even if the driving level is lowered and the execution of lane change control is started, the lane change control cannot be completed because the adjacent lane is actually congested, and the vehicle becomes immobile near the adjacent lane.

[0032] Furthermore, if monitoring for a predetermined period of time or longer does not result in the vehicle speed of other vehicles in the adjacent lane exceeding a predetermined speed, the system may suggest to the driver a manual lane change via the display 53 or speaker 54. The processor 10 suggests a manual lane change to the driver even if the speed of other vehicles traveling in the adjacent lane is below the predetermined speed, and if it receives confirmation input from the driver, it executes the first lane change control. The suggestion to the driver and confirmation by the driver are input and output via the input device 7 or the touch panel display 53 of the navigation device 5. This allows the lane change control to be executed even if the speed of other vehicles in the adjacent lane, which is the destination for the lane change, is below the predetermined speed, provided the driver performs confirmation input. In addition to the process of canceling the lane change control when traffic flow in the adjacent lane is stagnant, the lane change control can be executed by confirmation input. In other words, by receiving confirmation input from the driver, lane change control can be executed even when the adjacent lane is congested and the distance between vehicles is short.

[0033] <Third Embodiment> In this embodiment, we propose a method for transitioning driving levels in situations where a merge occurs after a branching point, as seen near interchanges and junctions. The processor 10 refers to map information 51 and determines whether the driving lane of the vehicle V1 branches off from the first main line and merges with a second main line different from the first main line within a predetermined distance. The processor 10 makes this determination 20 to 30 seconds before reaching the merging point. The predetermined distance may be defined in advance or may be defined according to the vehicle speed and the speed limit of the driving lane. If it is determined that the driving lane of the vehicle V1 branches off from the main line and merges with another main line within a predetermined distance, the process of transitioning from the first driving level to the second driving level is canceled, even if the second driving environment conditions are met. In other words, the first driving control at the first driving level is continued.

[0034] Figure 3 shows the position T of the vehicle V1 traveling in lane LX near an interchange or junction. In Figure 3, lane LX, on which vehicle V1 is traveling, branches off from the first main line L0, which runs along the X-axis in the figure, at point P1, and merges with the second main line L1 at point P2. The first main line L0 extends in the direction DX and intersects with the second main line L1 and its adjacent lane L2 at different elevations. Figure 3 shows only a portion of each lane, omitting the rest. Vehicle V1 travels in lane LX, which branches off from the first main line L0 at point P1, passes point P2, and then changes lanes from lane LX to the second main line L1. The position of vehicle V1 moves from position T0 before the branch, through position T1 on the branching road, through point T2, then to position T3, moves laterally, and moves to the second main line L1 at position T4 (changes lanes). The processor 10 refers to the map information 51 and determines whether or not the vehicle V1 should move to the driving lane LX that branches off from the first main line L0 and merges with the second main line L1 within a predetermined distance. If the first main line L1 (the lane to merge) is congested at point P2, where the vehicle branches off at point P1 and merges, and the speed of other vehicles V21-V24 is reduced, the vehicle V1 may not be able to change lanes to the first main line L1 due to the short distance between vehicles. If the system waits until it obtains the actual speed or distance between other vehicles V21-V24 at point P2, the lane change control may be suddenly canceled when approaching point P2. In that case, the time until the driver takes control of the driving will be shortened, and there will not be enough time to take over driving.

[0035] In contrast, in this embodiment, based on the map information 51, it is predicted that lane change control for merging will be executed within a predetermined distance from the branch, and even if the second driving environment conditions are met, the process of transitioning from the first driving level to the second driving level is canceled, and the first driving control at the first driving level is continued. This suppresses an increase in the driving level and makes it possible to prepare so that lane change control can be easily executed even before moving to the merging point. In this embodiment, in order to make it easy to execute lane change control before the vehicle V1 arrives at the merging point, even if automatic lane change control is not possible, preparation time can be provided to transfer the initiative of driving operation to the driver.

[0036] 100... Driving control system, 1... Driving control device, 10... Processor, 11... CPU, 12... ROM, 13... RAM, 2... Sensor, 21... Camera, 22... Radar device, 3... Vehicle information acquisition device, 4... Other vehicle information acquisition device, 5... Navigation device, 51... Map information, 52... Lane information, 6... Actuator, 61... Steering device, 62... Drive device, 63... Braking device, 7... Input device

Claims

1. A driving control method used in a processor to perform driving control to automatically drive the vehicle, wherein the processor performs first driving control by a first driving level when first driving environment conditions are met, and performs second driving control by a second driving level that is more advanced than the first driving level when second driving environment conditions are met, the second lane change conditions for determining whether or not to perform second lane change control by the second driving control are set to be relatively stricter than the first lane change conditions for determining whether or not to perform first lane change control by the first driving control, and when it is determined that the driving environment detected during the execution of the first driving control satisfies the second driving environment conditions, it is determined whether or not lane change control is necessary within a predetermined distance from the current position of the vehicle, and when it is determined that lane change control is necessary, the process of transitioning from the first driving level to the second driving level is stopped, and when it is determined that lane change control is not necessary, the process of transitioning from the first driving level to the second driving level is stopped.

2. The driving control method according to claim 1, wherein if the processor determines that lane change control is necessary, it continues the first driving control at the first driving level and executes the first lane change control, and if it determines that lane change control is not necessary, it transitions from the first driving level to the second driving level and executes the second driving control.

3. The driving control method according to claim 1 or 2, wherein the processor determines that lane change control is necessary, and the speed of another vehicle traveling in the adjacent lane to which the vehicle is moving due to the first lane change control is equal to or greater than a predetermined speed.

4. The driving control method according to any one of claims 1 to 3, wherein even if the processor determines that lane change control is necessary, it does not execute the first lane change control if the speed of another vehicle traveling in the adjacent lane to which the vehicle is moving due to the first lane change control is below a predetermined speed.

5. The driving control method according to claim 4, wherein the processor, upon receiving confirmation input from the driver of the vehicle, executes the first lane change control even if the speed of another vehicle traveling in an adjacent lane is less than the second predetermined speed.

6. The driving control method according to any one of claims 1 to 5, wherein the processor receives an input of a command to start a second lane change control from the driver of the vehicle in the second driving control, and receives an input of a driving operation for the first lane change control in the first driving control.

7. The driving control method according to any one of claims 1 to 6, wherein the processor refers to map information and determines that the vehicle's driving lane branches off from the first main line and merges with a second main line different from the first main line within a predetermined distance, and even if the second driving environment conditions are met, it cancels the process of transitioning from the first driving level to the second driving level and continues the first driving control at the first driving level.

8. A driving control device comprising a processor that executes driving control to automatically drive the vehicle, wherein the processor executes a first driving control at a first driving level when first driving environment conditions are met, executes a second driving control at a second driving level that is more advanced than the first driving level when second driving environment conditions are met, the second lane change conditions for determining whether or not to execute a second lane change control by the second driving control are set to be relatively stricter than the first lane change conditions for determining whether or not to execute a first lane change control by the first driving control, and when it is determined that the driving environment detected during the execution of the first driving control satisfies the second driving environment conditions, it determines whether or not lane change control is necessary within a predetermined distance from the current position of the vehicle, and when it is determined that lane change control is necessary, it cancels the process of transitioning from the first driving level to the second driving level, and when it is determined that lane change control is not necessary, it transitions from the first driving level to the second driving level.

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